1. Field of the Invention
The present invention relates generally to a device for jointing poles of a tent, and more particularly, to a pole jointing device for tents, which is used to joint a plurality of poles to each other to form a pole assembly which is inserted into pole assembly insert pockets sewn to the outer circumferential surface of the main body of a tent in order to obtain a desired shape when the tent is pitched, and which has a unit for automatically releasing the pole jointing device from its locking state when collapsing the tent, thus preventing the pole jointing device from being damaged.
2. Description of the Prior Art
Typically, tents have been designed to have a dome shape or a tunnel shape with a plurality of pole assemblies. Recently, demand has increased for a pole jointing device which allows the poles to be easily and simply connected to and disconnected from each other as well as prevents the tent from being deformed in its shape by an external force.
FIG. 1 shows a conventional tent having a tunnel shape, when the tent is pitched. In this tent, a plurality of pole assembly insert pockets 1a are sewn to the outer circumferential surface of a main body 1. In this case, the pole assemblies 2 are inserted into the pockets 1a in order that the tent may maintain a desired shape, that is, the tunnel shape. Each pole assembly 2 is formed by coupling a plurality of poles 2a with each other. The end of each pole is firmly connected to a rotor block 4 which is rotatable about a hinge 3a of a coupling member 3.
When it is required to pitch the tent 1, the pole assemblies 2 inserted in the pockets 1a sewn to the outer circumferential surface of the main body 1 are stretched. Then, all poles 2a forming each pole assembly 2 are rotated about the hinges 3a of the coupling members 3 such that the main body 1 of the tent forms a tunnel shape.
In the case where the tent 1 is pitched, when an external force is applied to the pole jointing parts of the pole assemblies 2, or the coupling members 3 installed at the ends of the poles 2a, the rotor blocks 4 connected to the coupling members 3 are rotated. On the contrary, when the external force is removed, the rotor blocks 4 are returned to their original positions by the elasticity of both the pockets 1a and the main body 1. In this way, the main body 1 of the tent can maintain the tunnel shape.
As described above, in the case where a relatively weak external force is applied to a coupling member 3, the pole assembly 2 can return to its original position. But, when a relatively strong external force, that is, force enough to rotate the rotor blocks 4 of the two neighboring coupling members 3, is applied to the coupling members 3, the poles 2a move toward the main body 1. At this time, even if the external force is removed, the poles 2a cannot return to their original positions. Thus, the conventional tent has a problem in that it is complicated to pitch the tent, because a user must adjust the main body 1 to have the tunnel shape while pulling the poles 2a inside and/or outside the tent such that the poles 2a are returned to their original positions.
In order to solve the problem, there has been proposed Korean Utility Model No. 0172539, which was filed to KIPO under U.M. Application No. 1999-0019685, and was registered on Dec. 13, 1999, and is titled xe2x80x9cDEVICE FOR JOINTING POLES OF A PORTABLE TENTxe2x80x9d. This pole jointing device is shown in FIGS. 2a to 2c. 
FIG. 2a, FIG. 2b, and FIG. 2c are, respectively, an exploded perspective view, a perspective view, and a plan view of the conventional pole jointing device. As shown in the drawings, the pole jointing device 10 according to the Utility Model No. 0172539 includes a housing 20 which is provided at its one end with a first pole insert hole 21 for receiving a pole 2a forming a pole assembly. A seat slit 22 is formed on the housing 20 in such a way as to be opposite to the pole insert hole 21. Further, two locking recesses 23 are formed on both sidewalls of the seat slit 22.
In the seat slit 22 is seated a rotor body 30. The rotor body 30 is provided with a longitudinal hinge hole 31 for receiving a hinge pin 40 which is used to joint the rotor body 30 to the housing 20. Two locking lugs 32 are integrally formed on both sidewalls of the rotor body 30, and are respectively inserted into the two locking recesses 23 formed on the housing 20. The rotor body 30 is provided at its one end with a second pole insert hole 33 for receiving another pole 2a. 
FIG. 3 is a front view of the tent, which is pitched by the pole assemblies each having been assembled by the conventional pole jointing device. As shown in FIG. 3, the pole assembly 2 is formed by jointing a plurality of poles 2a. In this case, two coupling members 3 and two pole jointing devices 10 are alternately installed on the pole assembly 2 at positions where the poles 2a are coupled to each other. In this case, the coupling member 3 is rotatable at both ends while the pole jointing device 10 is rotatably hinged at one end. Particularly, the pole jointing device 10 is installed at the jointing area of the poles 2a adjacent to the ground surface. The process of pitching the main body 1 of the tent using the pole assemblies 2, each of which is formed by two coupling members 3 and two pole jointing devices 10 is as follows. First, the rotor body 30 is inserted into the housing 20. At this time, the locking lugs 32 formed on the rotor body 30 are each fitted into an associated locking recess 23 of the housing 20, thus preventing an unexpected movement of the pole assembly 2. In such a way, as shown in FIG. 3, the tent is set up to have a tunnel shape.
When the external force is applied to the jointing area of the pole assembly 2 supporting the main body 1 of the tent, that is, the coupling member 3 and the pole jointing device 10 which are connected to the end of the pole 2a, the pole jointing device 10 is hinged, causing the external force to be transmitted to the coupling member 3 adjacent to the pole jointing device 10. At this time, the rotor block 4, mounted to the coupling member 3, is rotated. On the other hand, when the external force is removed from the coupling member 3, the rotor block 4 is returned to its original position from a rotated position by the elasticity of both the main body 1 and the pocket 1a. In this way, the tent 1 maintains the tunnel shape.
The pole jointing device 10 allows the tent to be invariable in its shape, thus preventing the pole assembly from folding.
Further, when removing the pole connecting force from the pole assembly 2 to collapse the main body 1 of the tent, the rotor block 4 of each coupling member 3 is rotated while the rotor body 30 inserted into the ho sing 20 of the pole jointing device 10 is pulled out from the housing 20 along the longitudinal hinge hole 31. At this time, the locking lugs 32 formed on the rotor body 30 are removed from the locking recesses 23, so the rotor body 30 rotates about the hinge part, thus collapsing the tent.
However, the conventional pole jointing device has a problem in that it is complicated to collapse the tent, beta se the rotor body 30 must be rotated after the locking lugs 32 are removed from the locking recesses 23 of the housing 20 when the tent""s collapse is required.
The conventional pole jointing device has another problem in that the locking lugs 32 and locking recesses 23 may be damaged if a user rotates the rotor body 30 without the locking lugs 32 being removed from the locking recesses 23, so the broken pole jointing device has to be replaced with a new one, thus resulting in additional expense.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a device for jointing poles of a tent, which is designed to automatically remove locking lugs from locking recesses, different from the conventional pole jointing device that is designed such that the locking lugs must be removed from the locking recesses of a housing before rotating a rotor body to collapse the tent, and which thus prevents the locking lugs and the locking recesses from being damaged when rotating the rotor body without the locking lugs being removed from the locking recesses.
In order to accomplish the above object, the present invention provides a device for jointing poles of a tent, comprising a housing consisting of a first pole insert hole for receiving a pole, a seat slit in which a rotor body is seated, and a locking recess formed on each sidewall of the seat slit; and a rotor body consisting of a longitudinal hinge hole receiving a hinge pin therein such that the rotor body seated in the seat slit of the housing is rotatably jointed to the housing, a locking lug inserted into an associated locking recess of the housing to limit the rotation of the rotor body, and a second pole insert hole for receiving another pole, further comprising: a unit for automatically releasing the rotor body from the housing, the automatic releasing unit consisting of an elastic member mounted by a locking member to an end wall provided at the inside end of the seat slit, with the elastic member allowing the locking lugs of the rotor body to be automatically removed from the locking recesses of the housing when collapsing the tent.